This present invention relates to an improvement in free-standing mortarless building structures and, in particularly, to a virtually mortarless interconnecting block system with unique dynamic properties.
Typically speaking, free-standing masonry walls are constructed of concrete blocks (or similar material) in running courses. Each course is placed in such a manner so that the vertical joints are staggered from e previous course. Mortar is used as a binding agent between the courses between the ends of each of the blocks. Conventional concrete blocks typically have one or more voids extending through them in the vertical direction to create vertical columns through the walls. Reinforcing bars are placed in these columns for enclosure within a continuous mortar masses within the columns, in accordance with building code standards. Such columns typically are placed approximately four feet apart along the length of the wall.
Although this type of free-standing masonry wall has been used successfully in residential, commercial and industrial construction, it possesses a considerable number of drawbacks. These include: the necessity of skilled labor for assembly (not handyman friendly), the requirement of mortar as a binding agent between each of the components, the considerable time demanded for construction, the inability to disassemble components and reuse if desired, the incapacity to absorb external pressure changes (such as settling, hydrostatic pressure and seismic disturbances) without significant deterioration to the structural integrity.
Several types of blocks and wall systems have been proposed to overcome some of these deficiencies. Beginning in 1901, U.S. Pat. No. 676,803 to Shaw, disclosed an interlocking block system that employed a combination of tongues and groves along with dovetails to secure each block to the adjacent blocks. This was followed by similar designs in U.S. Pat. No. 690,811 to Waller, U.S. Pat. No. 748,603 to Henry; U.S. Pat. No. 868,838 to Brewington; U.S. Pat. No. 1,562,728 to Albrecht; U.S. Pat. No. 2,902,853 Loftstrom; and, French Patent No. 1,293,147. Although the use of interlocking male and female dovetails provide a positive lock and represent a significant improvement over similar tongue and grove construction, all of the dovetails used in this conventional art embody a critical disadvantage in terms of assembly. When these are employed (as in the case of: U.S. Pat. No. 676,803; French Patent No. 1,293,147; U.S. Pat. Nos. 748,603; 1,562,728; and, 2,902,853) on the upper and lower surfaces of the block, the female dovetail of each new block must be slid over a number of male dovetails on the lower course into the appropriate position. Given the dimensional inaccuracies of common block material along with the tolerances necessary to slide the new block into place, binding is a frequent occurrence. Despite a long-felt but unresolved need for handyman friendly construction material, this frequent assembly problem, along with the various proprietary components, kept assembly to skilled professionals.
While much of the conventional art, to a certain degree, overcomes some of the difficulties associated with the requirement of mortar, and the inability to disassemble, none provide for the capacity to automatically absorb external pressure changes without significant deterioration in structural integrity. Attempts to address this particular problem have come in the form of steel reinforcement of some kind. In 1907, U.S. Pat. No. 859,663 to Jackson employed steel post, tension-threaded reinforcement rods in combination with steel frames to produce a very strong wall. The use of steel post, tension-threaded reinforcement rods can also be seen in: U.S. Pat. No. 3,378,96 to Larger; U.S. Pat. No. 859,663 to Jackson; U.S. Pat. No. 4,726,567 to Greenburg; U.S. Pat. No. 5,138,808 to Bengtson et al.; and, U.S. Pat. No. 5,355,647 to Johnson et al.
Unfortunately, this move to steel reinforcement as a means to counter external pressure meant the loss of many of the gains achieved by much of the conventional art. In short, the characteristics of: mortarless construction and the ability to disassemble components and reuse them were sacrificed for a stronger wall.
Although the addition of steel to bind the wall in a solid mass contributed to it structural integrity by better resisting certain external forces, this is only true in the case of a force applied in one direction against the wall. As in the case of hydrostatic pressure, the force moves only in one direction; from the outside to the inside, slowly and steadily. Seismic disturbances, such as those associate with earthquakes, tend to move the earth in a rapid back and forth motion. A wall bound as a sold mass is unable to accommodate the dynamic back and forth movement. Instead, its rigid composition directly transfers the force to the rest of the building (acting as sort of a lever) weakening the integrity of the entire structure until it finally fails.
Thus, it is desirable to provide a masonry wall system that incorporates the advantages of: unskilled labor for assembly; mortarless construction; the ability to disassemble and reuse; and, the necessary capacity to automatically absorb external pressure changes (particularly seismic disturbances) without significant deterioration of structural integrity. Such a wall system would create a new synergy that would satisfy a long-felt but unresolved need. It would also represent a positive contribution to the masonry industry.
Accordingly it is an object of the present invention to provide an improved masonry walls system that does not require skilled labor to assemble.
It is another object of the present invention to provide a masonry wall system that does not require mortar for it""s construction.
It is a further object of the present invention to provide an improved masonry wall system that is capable of rapid, on-site assembly.
It is still another object of the present invention to provide an improve masonry wall system that can be disassembled and then reused. It is still an additional object of the present invention to provide an improved masonry wall system that overcomes the conventional problems of masonry assembly in which dovetail structures are used.
It is yet another object of the present invention to provide an improved masonry wall system that is capable of absorbing external pressure changes (such as settling, hydrostatic pressure and seismic disturbances) without significant deterioration in the structural integrity of the wall system.
It is yet a further object of the present invention to provide an improved masonry wall system that is capable of distributing stress on any portion of the wall throughout a large surrounding segment of the wall.
It is again another object of the present invention to provide an improved masonry wall system having a wide variety of interlocking schemes to facilitate flexibility in wall design and construction.
It is still a further object of the present invention to provide an improved masonry wall system that has superior earthquake-resistant properties to conventional masonry wall systems.
It is yet a further object of the present invention to provide a model system for an improved, mortarless wall system.
It is again another object of the present invention to provide a mortarless masonry wall system in which no vertical seams between adjacent blocks are lined from row to row, thereby strengthening the wall system.
It is still a further object of the present invention to provide a mortarless masonry wall system in which individual blocks interlock with each other, both vertically and horizontally, using self-contained structures.
It is an additional object of the present invention to provide a mortarless masonry wall system constituted by blocks which are easily handled, and quickly and efficiently assembled.
It is yet another object of the present invention to provide a mortarless masonry wall system which is flexible in order to compensate for external stresses on the wall such as seismic activity.
It is again another object of the present invention to provide a mortarless masonry wall system having adjustable degrees of flexibility once the wall has been assembled, without requiring changes in the size and structure of the individual blocks.
It is an additional object of the present invention to provide a mortarless masonry wall system admitting to easy insertion of insulating cords.
It is again a further object of the present invention to provide a mortarless masonry wall system which eliminates or greatly reduces point loading between blocks of the wall.
It is yet another object of the present invention to provide a mortarless masonry wall system admitting to varying degrees of adjustable flexibility, even after the wall has been entirely assembled.
It is again a further object of the present invention to provide a mortarless masonry wall system which is capable of extending its flexibility through the use of additional structures added after the wall is assembled.
It is an additional object of the present invention to provide a mortarless masonry wall system which relies upon only two types of different blocks, thereby simplifying production of the wall component and ease of assembly.
It is again a further object of the present invention to provide a mortarless masonry wall system having the capability of both flexing and returning to its original position after the removal of external stresses.
It is yet another object of the present invention to provide a mortarless masonry wall system which is flexible and avoids the necessity of forming rebar holes through the block constituting the wall.
It is still a further object of the present invention to provide a mortarless masonry wall system which easily drains water from the interior of the wall into drainage systems at the foot of the wall.
It is yet a further object of the present invention to provide a mortarless masonry wall system which includes internal spaces for conduit within the blocks constituting the wall without the necessity of cutting holes through the transverse walls of the block.
It is yet a further object of the present invention to provide a mortarless masonry wall system which is flexible but provides for horizontal structures such as lintels.
It is again another object of the present invention to provide a mortarless masonry wall system which admits to horizontal reinforcement through the adjustment of horizontal pressure on the blocks of the wall.
It is still another object of the present invention to provide a mortarless masonry wall system, and a technique for installing the wall system whereby the blocks of the wall are properly aligned to the footer supporting the wall.
It is still an additional object of the present invention to provide a mortarless masonry wall system in which the wall system is easily sectionalized and braced on a vertical basis for separating different stories for buildings employing said wall system.
It is again a further object of the present invention to provide a mortarless masonry wall system wherein reinforcement is easily added to the walls by virtue of metal reenforcing structures.
These and other objects and goals of the present invention are achieved by a flexible interlocking wall system including a plurality of blocks arranged for interlocking without mortar, where the wall system has at least two major surfaces, each major surface forming a wall face. The wall system includes a plurality of main blocks where each main block has at least one stabilizing slot. The stabilizing slot is positioned to be at lest partially vertically collinear with stabilizing slots in other vertically adjacent blocks when positioned with respect to each other in an interlocking configuration to form a wall face. Also included are a plurality of reinforcing tendons, each placed in a selected stabilizing slot through a plurality of the main blocks. Each of the reinforcing tendons is sized with respect to the stabilizing slot to permit movement of the main block along at least one horizontal plane for a predetermined extent in a direction perpendicular to at least one face of the wall. Each of the reinforcing tendons is connected inside the wall at one end and connected at the top of the wall at the other end.